Test apparatus for testing devices under test and method for transmitting a test signal

Abstract

A test apparatus comprises an input for receiving a test signal from a test signal source, wherein a signal line with a predefined characteristic wave impedance can be connected to the input. The test apparatus further comprises branching means with a first and a plurality of second terminals, the first terminal being connected to the input. The test apparatus further comprises a plurality of distribution lines, wherein each distribution line is connected to one of the plurality of second terminals of branching means, wherein one of the devices under test can be connected to each distribution line at the output side, each distribution line having a characteristic wave impedance, which is substantially equal to the product of the predefined characteristic wave impedance of the signal line and the number of distribution lines. Thus, a signal matching is given at the branching point, so that no amplitude or signal rise time distortions of the excitation signals occur at the inputs of the devices under test.

What is claimed is:  
     
       1. Test apparatus for testing devices under test, comprising: 
       an input for receiving a test signal from a test signal source, wherein a signal line with a predefined characteristic wave impedance is connectable to the input;  
       branching means with a first and a plurality of second terminals, the first terminal being connected to the input; and  
       a plurality of distribution lines, each distribution line of the plurality of distribution lines being connected to one of the plurality of second terminals on the input side, and wherein one of the devices under test is connectable to each distribution line on an output side, wherein each distribution line has a characteristic wave impedance which is substantially equal to a product of the predefined characteristic wave impedance and the number of distribution lines.  
     
     
       2. Test apparatus according to  claim 1 , wherein the input is formed to be able to be connected to a coaxial cable as a signal line. 
     
     
       3. Test apparatus according to  claim 1 , wherein the distribution lines are strip lines. 
     
     
       4. Test apparatus according to  claim 1 , wherein the test apparatus is formed as a contact board. 
     
     
       5. Test apparatus according to  claim 1 , wherein the distribution lines all have the same length. 
     
     
       6. Test apparatus according to  claim 1 , wherein the predefined characteristic wave impedance of the signal line is 50 Ω or smaller. 
     
     
       7. Test apparatus according  claim 1 , wherein inputs of the devices under test that are connectable to the distribution lines have a high impedance. 
     
     
       8. Method for transmitting a test signal to devices under test, comprising: 
       receiving a test signal from a signal line having a predefined characteristic wave impedance;  
       branching the testing signal into a number of branching signals;  
       transmitting the branching signals via a number of distribution lines, wherein each distribution line has a characteristic wave impedance that is substantially equal to a product of the predefined characteristic wave impedance and the number of distribution lines.